Alcohol withdrawal: effects of clonidine treatment on sympathetic activity, the renin-aldosterone system, and clinical symptoms

Management of alcohol withdrawal syndromes in general hospital settings

The covid-19 pandemic was associated with an unprecedented increase in alcohol consumption and associated morbidity, including hospitalizations for alcohol withdrawal. Clinicians based in hospitals must be ready to identify, assess, risk-stratify, and treat alcohol withdrawal with evidence based interventions. In this clinically focused review, we outline the epidemiology, pathophysiology, clinical manifestations, screening, assessment, and treatment of alcohol withdrawal in the general hospital population. We review and summarize studies addressing the drug treatment of alcohol withdrawal syndromes in inpatient populations, with a focus on the use of benzodiazepine drugs, phenobarbital, antiseizure drugs, and α-2 adrenergic drugs. Emerging areas of interest include the use of novel alcohol biomarkers, risk stratification instruments, alternative symptom severity scales, severe withdrawal syndromes resistant to benzodiazepine drugs, and treatment protocol variations-including non-symptom-triggered and benzodiazepine-sparing protocols. We identify key areas for research including identification of populations who will benefit from non-benzodiazepine strategies, more individualized risk stratification approaches to guide treatment, and greater inclusion of gender and racial and ethnic minorities in future studies.

Psychopharmacology of smoking cessation medications: focus on patients with mental health disorders

The adverse effects of smoking cessation in individuals with mental health disorders have been a point of concern, and progress in the development of treatment has been slow. The primary first-line treatments for smoking cessation are Nicotine Replacement Therapy, Bupropion, Varenicline, and behavioural support. Nortriptyline and Clonidine are second-line treatments used when the first-line treatments are not effective or are contraindicated. Smoking cessation medications have been shown to be effective in reducing nicotine cravings and withdrawal symptoms and promoting smoking cessation among patients living with mental disorders. However, these medications may have implications for patients' mental health and need to be monitored closely. The efficacy and side effects of these medications may vary depending on the patient's psychiatric condition, medication regimen, substance use, or medical comorbidities. The purpose of this review is to synthesise the pharmacokinetics, pharmacodynamics, therapeutic effects, adverse effects, and pharmacological interactions of first- and second-line smoking cessation drugs, with an emphasis on patients suffering from mental illnesses. Careful consideration of the risks and benefits of using smoking cessation medications is necessary, and treatment plans must be tailored to individual patients' needs. Monitoring symptoms and medication regimens is essential to ensure optimal treatment outcomes.

Drug addiction co-morbidity with alcohol: Neurobiological insights

Addiction is a chronic disorder that consists of a three-stage cycle of binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These stages involve, respectively, neuroadaptations in brain circuits involved in incentive salience and habit formation, stress surfeit and reward deficit, and executive function. Much research on addiction focuses on the neurobiology underlying single drug use. However, alcohol use disorder (AUD) can be co-morbid with substance use disorder (SUD), called dual dependence. The limited epidemiological data on dual dependence indicates that there is a large population of individuals suffering from addiction who are dependent on more than one drug and/or alcohol, yet dual dependence remains understudied in addiction research. Here, we review neurobiological data on neurotransmitter and neuropeptide systems that are known to contribute to addiction pathology and how the involvement of these systems is consistent or divergent across drug classes. In particular, we highlight the dopamine, opioid, corticotropin-releasing factor, norepinephrine, hypocretin/orexin, glucocorticoid, neuroimmune signaling, endocannabinoid, glutamate, and GABA systems. We also discuss the limited research on these systems in dual dependence. Collectively, these studies demonstrate that the use of multiple drugs can produce neuroadaptations that are distinct from single drug use. Further investigation into the neurobiology of dual dependence is necessary to develop effective treatments for addiction to multiple drugs.

Absorption of Clonidine from a Halved Transdermal System — A Pilot Study

Objective:

To assess whether clonidine bioavailability is compromised when a transdermal system is cut in half.

Methods:

Seven healthy volunteers were enrolled in this prospective crossover study. In phase I, an intact clonidine 0.1 mg/24 h transdermal system (TS-1) was applied and plasma clonidine concentration was obtained 72 hours after application, after steady-state (48–72 hours) was purported to have been reached. After a minimum seven-day washout period, half of a clonidine 0.2 mg/24 h transdermal system (½TS-2) was applied in phase II, with plasma clonidine concentrations obtained at 24, 48, 72, 120, and 192 hours following application.

Results:

Mean plasma clonidine concentrations at 72 hours with TS-1 in phase I were 0.17 ± 0.07 ng/mL. Mean plasma clonidine concentrations at 24, 48, 72, 120, and 192 hours with ½TS-2 in phase II were 0.16 ± 0.11, 0.15 ± 0.06, 0.15 ± 0.05, 0.19 ± 0.4, and 0.20 ± 0.8 ng/mL, respectively. There was no statistically significant difference between mean concentrations at 72 hours in phases I and II, but individual clonidine concentrations between phases varied 50–286%. Individual concentration versus time curves obtained from subjects in phase II lacked a consistent pattern.

Conclusions:

Although there was no statistically significant difference in mean concentrations at 72 hours, individual clonidine concentration variations may have a clinically significant impact. The lack of a consistent plasma concentration versus time pattern may also be of clinical concern. Based on these results, cutting the clonidine transdermal system may compromise its integrity, and is therefore not recommended.

Is it prime time for alpha2-adrenocepter agonists in the treatment of withdrawal syndromes?

The need to treat withdrawal syndromes is a common occurrence in outpatient, inpatient ward, and intensive care unit (ICU) settings. A PubMed and Google Scholar search using alpha2-adrenoreceptor agonist (A2AA), specific A2AA agents, withdrawal syndrome and nicotine, and alcohol and opioid withdrawal terms was performed. A2AA agents appear to be able to modulate many of the signs and symptoms of significant withdrawal syndromes but are also capable of significant side effects, which can limit clinical use. Non-opioid oral A2AA agent use for opioid withdrawal has been well established. Pharmacologic combination therapy that utilizes A2AA agents for withdrawal syndromes appears promising but requires further formal testing to better define which other agents, under what condition(s), and at what A2AA doses are needed. The A2AA dexmedetomidine may be useful as an adjunctive agent in treating severe alcohol withdrawal syndromes in the ICU. In general, the current data does not support the routine use of A2AA as the primary or sole agent to treat ethanol/alcohol or nicotine withdrawal syndromes. Specific A2AA agents such as lofexidine has been shown to have a primary role in non-opioid-based treatment of opioid withdrawal syndrome and dexmedetomidine in combination with benzodiazepines has been shown to have potential in the treatment of severe ICU-based alcohol withdrawal syndrome.

Influence of dexmedetomidine therapy on the management of severe alcohol withdrawal syndrome in critically ill patients

PURPOSE

Although benzodiazepines are first-line drugs for alcohol withdrawal syndrome (AWS), rapidly escalating doses may offer little additional benefit and increase complications. The purpose of this study was to evaluate dexmedetomidine's impact on benzodiazepine requirements and hemodynamics in AWS.

MATERIALS AND METHODS

This retrospective case series evaluated 33 critically ill adults with a primary diagnosis of AWS from 2006 to 2012 at an academic medical center.

RESULTS

Dexmedetomidine began a median (interquartile range) of 11 (2, 32) hours into intensive care unit admission and was titrated to an infusion rate of 0.7 (0.4, 0.7) μg kg(-1) h(-1) to achieve the desired depth of sedation. In the 12 hours after dexmedetomidine began, patients experienced a 20-mg reduction in median cumulative benzodiazepine dose used (P < .001), a 14-mm Hg lower mean arterial pressure (P = .03), and a 17-beats/min reduction in median heart rate (P < .001). Four (12%) patients experienced hypotension (systolic blood pressure <80 mm Hg) during therapy, and there were no cases of bradycardia (heart rate <40 beats/min).

CONCLUSION

Dexmedetomidine decreased benzodiazepine requirements and improved the overall hemodynamic profile of patients with severe AWS. These results provide promising evidence about the potential benefit of dexmedetomidine for AWS.

Elevated Norepinephrine may be a Unifying Etiological Factor in the Abuse of a Broad Range of Substances: Alcohol, Nicotine, Marijuana, Heroin, Cocaine, and Caffeine

A wide range of commonly abused drugs have effects on the noradrenergic neurotransmitter system, including alterations during acute intoxication and chronic use of these drugs. It is not established, however, that individual differences in noradrenergic signaling, which may be present prior to use of drugs, predispose certain persons to substance abuse. This paper puts forth the novel hypothesis that elevated noradrenergic signaling, which may be raised largely due to genetics but also due to environmental factors, is an etiological factor in the abuse of a wide range of substances, including alcohol, nicotine, marijuana, heroin, cocaine, and caffeine. Data are reviewed for each of these drugs comprising their interaction with norepinephrine during acute intoxication, long-term use, subsequent withdrawal, and stress-induced relapse. In general, the data suggest that these drugs acutely boost noradrenergic signaling, whereas long-term use also affects this neurotransmitter system, possibly suppressing it. During acute withdrawal after chronic drug use, noradrenergic signaling tends to be elevated, consistent with the observation that norepinephrine lowering drugs such as clonidine reduce withdrawal symptoms. Since psychological stress can promote relapse of drug seeking in susceptible individuals and stress produces elevated norepinephrine release, this suggests that these drugs may be suppressing noradrenergic signaling during chronic use or instead elevating it only in reward circuits of the brain. If elevated noradrenergic signaling is an etiological factor in the abuse of a broad range of substances, then chronic use of pharmacological agents that reduce noradrenergic signaling, such as clonidine, guanfacine, lofexidine, propranolol, or prazosin, may help prevent or treat drug abuse in general.

Current and emerging pharmacotherapeutic options for smoking cessation

Tobacco smoking remains the single most preventable cause of morbidity and mortality in developed countries and poses a significant threat across developing countries where tobacco use prevalence is increasing. Nicotine dependence is a chronic disease often requiring multiple attempts to quit; repeated interventions with pharmacotherapeutic aids have become more popular as part of cessation therapies. First-line medications of known efficacy in the general population include varenicline tartrate, bupropion hydrochloride, nicotine replacement therapy products, or a combination thereof. However, less is known about the use of these products in marginalized groups such as the indigenous, those with mental illnesses, youth, and pregnant or breastfeeding women. Despite the efficacy and safety of these first line pharmacotherapies, many smokers continue to relapse and alternative pharmacotherapies and cessation options are required. Thus, the aim of this review is to summarize the existing and developing pharmacotherapeutic and other options for smoking cessation, to identify gaps in current clinical practice, and to provide recommendations for future evaluations and research.

Role of α2-agonists in the treatment of acute alcohol withdrawal

OBJECTIVE

To evaluate literature reporting on the role of norepinephrine in alcohol withdrawal and to determine the safety and efficacy of α(2)-agonists in reducing symptoms of this severe condition.

DATA SOURCES

Articles evaluating the efficacy and safety of the α(2)-agonists clonidine and dexmedetomidine were identified from an English-language MEDLINE search (1966-December 2010). Key words included alcohol withdrawal, delirium tremens, clonidine, dexmedetomidine, α(2)-agonist, norepinephrine, and sympathetic overdrive.

STUDY SELECTION AND DATA EXTRACTION

Studies that focused on the safety and efficacy of clonidine and dexmedetomidine in both animals and humans were selected.

DATA SYNTHESIS

The noradrenergic system, specifically sympathetic overdrive during alcohol withdrawal, may play an important role in withdrawal symptom development. Symptoms of sympathetic overdrive include anxiety, agitation, elevated blood pressure, tachycardia, and tremor. Therefore, α(2)-agonists, which decrease norepinephine release, may have a role in reducing alcohol withdrawal symptoms. The majority of controlled animal and human studies evaluated clonidine, but the most recent literature is from case reports on dexmedetomidine. The literature reviewed here demonstrate that these 2 α(2)-agonists safely and effectively reduce symptoms of sympathetic overdrive and concomitant medication use. Dexmedetomidine may offer an advantage over current sedative medications used in the intensive care unit, such as not requiring intubation with its use, and therefore further study is needed to fully elicit its benefit in alcohol withdrawal.

CONCLUSION

Clonidine and dexmedetomidine may provide additional benefit in managing alcohol withdrawal by offering a different mechanism of action for targeting withdrawal symptoms. Based on literature reviewed here, the primary role for clonidine and dexmedetomidine is as adjunctive treatment to benzodiazepines, the standard of care in alcohol withdrawal.

Anticonvulsants for alcohol withdrawal

BACKGROUND

Alcohol abuse and dependence represents a most serious health problem worldwide with major social, interpersonal and legal interpolations. Besides benzodiazepines, anticonvulsants are often used for the treatment of alcohol withdrawal symptoms. Anticonvulsants drugs are indicated for the treatment of alcohol withdrawal syndrome, alone or in combination with benzodiazepine treatments. In spite of the wide use, the exact role of the anticonvulsants for the treatment of alcohol withdrawal has not yet bee adequately assessed.

OBJECTIVES

To evaluate the effectiveness and safety of anticonvulsants in the treatment of alcohol withdrawal.

SEARCH STRATEGY

We searched Cochrane Drugs and Alcohol Group' Register of Trials (December 2009), PubMed, EMBASE, CINAHL (1966 to December 2009), EconLIT (1969 to December 2009). Parallel searches on web sites of health technology assessment and related agencies, and their databases.

SELECTION CRITERIA

Randomized controlled trials (RCTs) examining the effectiveness, safety and overall risk-benefit of anticonvulsants in comparison with a placebo or other pharmacological treatment. All patients were included regardless of age, gender, nationality, and outpatient or inpatient therapy.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and extracted data from studies.

MAIN RESULTS

Fifty-six studies, with a total of 4076 participants, met the inclusion criteria. Comparing anticonvulsants with placebo, no statistically significant differences for the six outcomes considered.Comparing anticonvulsant versus other drug, 19 outcomes considered, results favour anticonvulsants only in the comparison carbamazepine versus benzodiazepine (oxazepam and lorazepam) for alcohol withdrawal symptoms (CIWA-Ar score): 3 studies, 262 participants, MD -1.04 (-1.89 to -0.20), none of the other comparisons reached statistical significance.Comparing different anticonvulsants no statistically significant differences in the two outcomes considered.Comparing anticonvulsants plus other drugs versus other drugs (3 outcomes considered), results from one study, 72 participants, favour paraldehyde plus chloral hydrate versus chlordiazepoxide, for the severe-life threatening side effects, RR 0.12 (0.03 to 0.44).

AUTHORS' CONCLUSIONS

Results of this review do not provide sufficient evidence in favour of anticonvulsants for the treatment of AWS. There are some suggestions that carbamazepine may actually be more effective in treating some aspects of alcohol withdrawal when compared to benzodiazepines, the current first-line regimen for alcohol withdrawal syndrome. Anticonvulsants seem to have limited side effects, although adverse effects are not rigorously reported in the analysed trials.

Pharmacotherapy of alcohol and drug problems

Substantial progress has been made in the pharmacotherapy of withdrawal syndromes and organic complications of alcohol and drug abuse. Diazepam loading (alcohol withdrawal), phenobarbital loading (barbituate withdrawal) and diazepam tapering (benzodiazepine discontinuation) have considerably simplified treatment of withdrawal syndromes and have enhanced efficacy. Propylthiouracil shows considerable promise in the out-patient treatment of alcoholic liver disease. New medications, particularly those modifying serotonergic function, have efficacy in decreasing alcohol consumption and show considerable therapeutic potential. Human pharmacology and pharmacotherapy should be a central part of training programmes in the field in order that further advances can be made.

Non-Nicotinic Therapies for Smoking Cessation

Cigarette smoking is the primary cause of numerous preventable diseases; as such, the goals of smoking cessation are both to reduce health risks and to improve the quality of life. Currently, the first-line smoking cessation therapies include nicotine replacement products and bupropion. The nicotinic receptor partial agonist varenicline has recently been approved by the FDA for smoking cessation. A newer product currently under development and seeking approval by the FDA are nicotine vaccines. Clonidine and nortriptyline have demonstrated some efficacy but side effects may limit their use to second-line therapeutic products. Other therapeutic drugs that are under development include rimonabant, mecamylamine, monoamine oxidase inhibitors, and dopamine receptor D3 antagonists. Inhibitors of nicotine metabolism are also promising candidates for smoking reduction and cessation. In conclusion, promising new therapeutic products are emerging and they will provide smokers additional options to assist in achieving smoking cessation.

Current and emerging pharmacotherapies for treating tobacco dependence

Tobacco dependence remains the leading cause of death and disease in the US and a major cause of mortality around the world, yet 1 out of 5 American adults smoke and 1.3 billion adults smoke worldwide. Nicotine replacement therapies (NRTs), bupropion and varenicline, are approved by the US FDA as first-line treatments for nicotine dependence. Clonidine and nortriptyline are recommended as second-line treatments by the Agency for Healthcare Research and Quality. Although recent data suggest that varenicline is superior to bupropion for treating nicotine dependence, a majority of smokers fail to maintain long-term abstinence from smoking using FDA-approved pharmacotherapies. Thus, continued investigation of novel medications for nicotine dependence remains a critical priority. Guided by research on multiple neurobiological mechanisms of nicotine dependence, several novel medications that mimic and/or attenuate nicotine's rewarding effects, or reduce nicotine withdrawal, are under investigation. Although existing data are limited or conflicting, there is some evidence for the efficacy of selegiline, fluoxetine, naltrexone and mecamylamine in certain subgroups of smokers. New research directions, such as fast-acting NRTs, the tailored use of NRTs for subtypes of smokers, and pharmacogenetics, hold promise for new treatment approaches and, ultimately, for reducing rates of tobacco use in the US and worldwide.

Anticonvulsants for alcohol withdrawal

BACKGROUND

Alcohol withdrawal syndrome is a cluster of symptoms that occurs in alcohol-dependent people after cessation or reduction in alcohol use. This systematic review focuses on the evidence of anticonvulsants' use in the treatment of alcohol withdrawal symptoms.

OBJECTIVES

To evaluate the effectiveness and safety of anticonvulsants in the treatment of alcohol withdrawal.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004); MEDLINE (1966 to October 2004); EMBASE (1988 to October 2004) and EU-PSI PSI-Tri database with no language and publication restrictions and references of articles.

SELECTION CRITERIA

All randomized controlled trials examining the effectiveness, safety and overall risk-benefit of an anticonvulsant in comparison with a placebo or other pharmacological treatment or another anticonvulsant were considered.

DATA COLLECTION AND ANALYSIS

The authors independently assessed trial quality extracted data.

MAIN RESULTS

Forty-eight studies, involving 3610 people were included. Despite the considerable number of randomized controlled trials, there was a variety of outcomes and of different rating scales that led to a limited quantitative synthesis of data. For the anticonvulsant versus placebo comparison, therapeutic success tended to be more common among the anticonvulsant-treated patients (relative risk (RR) 1.32; 95% confidence interval (CI) 0.92 to 1.91), and anticonvulsant tended to show a protective benefit against seizures (RR 0.57; 95% CI 0.27 to 1.19), but no effect reached formal statistical significance. For the anticonvulsant versus other drug comparison, CIWA-Ar score showed non-significant differences for the anticonvulsants compared to the other drugs at the end of treatment (weighted mean difference (WMD) -0.73; 95% CI -1.76 to 0.31). For the subgroup analysis of carbamazepine versus benzodiazepine, a statistically significant protective effect was found for the anticonvulsant (WMD -1.04; 95% CI -1.89 to -0.20), p = 0.02), but this was based on only 260 randomized participants. There was a non-significant decreased incidence of seizures (RR 0.50; 95% CI 0.18 to 1.34) favouring the patients that were treated with anticonvulsants than other drugs, and side-effects tended to be less common in the anticonvulsant-group (RR 0.56; 95% CI 0.31 to 1.02).

AUTHORS' CONCLUSIONS

It is not possible to draw definite conclusions about the effectiveness and safety of anticonvulsants in alcohol withdrawal, because of the heterogeneity of the trials both in interventions and the assessment of outcomes. The extremely small mortality rate in all these studies is reassuring, but data on other safety outcomes are sparse and fragmented.

Intrathecal and oral clonidine as prophylaxis for postoperative alcohol withdrawal syndrome: a randomized double-blinded study

In this study, we evaluated the effect of intrathecal and oral clonidine as supplements to spinal anesthesia with lidocaine in patients at risk of postoperative alcohol withdrawal syndrome (AWS). We hypothesized that clonidine would have a prophylactic effect on postoperative AWS. Forty-five alcohol-dependent patients (daily ethanol intake >60 g) scheduled for transurethral resection of the prostate were double-blindly randomized into three groups. All patients received hyperbaric lidocaine 100 mg intrathecally. The diazepam group (DiazG) was premedicated with diazepam 10 mg orally; the intrathecal clonidine group (Clon(i/t)G) received a placebo (saline) tablet and clonidine 150 microg intrathecally; and the oral clonidine group (Clon(p/o)G) received clonidine 150 microg orally. For patients diagnosed with AWS, the Clinical Institute Withdrawal Assessment for Alcohol, revised scale, was used. Twelve patients in the DiazG had symptoms of AWS, compared with two in the Clon(i/t)G and one in the Clon(p/o)G. The median Clinical Institute Withdrawal Assessment for Alcohol, revised scale, score was 12 in the DiazG versus 1 in the clonidine-treated groups. Two patients in the DiazG had severe delirium. Patients receiving oral clonidine had a slightly decreased mean arterial blood pressure 6-12 h after spinal anesthesia (P < 0.05); patients in the DiazG had a hyperdynamic circulatory reaction 24-72 h after surgery. In conclusion, preoperative clonidine 150 microg, intrathecally or orally, prevented significant postoperative AWS in ethanol-dependent patients.

IMPLICATIONS

In this randomized, double-blinded study, clonidine 150 microg both intrathecally and orally prevented postoperative alcohol-withdrawal symptoms in alcohol-dependent men. The effect was superior to that with a single dose of diazepam 10 mg orally.

Clonidine for smoking cessation

BACKGROUND

Clonidine was originally used to lower blood pressure. It acts on the central nervous system and may reduce withdrawal symptoms in various addictive behaviours, including tobacco use.

OBJECTIVES

The aim of this review is to determine clonidine's effectiveness in helping smokers to quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register for trials of clonidine. Date of the most recent search: May 2004.

SELECTION CRITERIA

We considered randomized trials of clonidine versus placebo with a smoking cessation endpoint assessed at least 12 weeks following the end of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the dose and duration of clonidine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least 12 weeks follow up in patients smoking at baseline. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effect model.

MAIN RESULTS

Six trials met the inclusion criteria. There were three trials of oral, and three of transdermal clonidine. Some form of behavioural counselling was offered to all participants in five of the six trials. There was a statistically significant effect of clonidine in one of these trials. The pooled odds ratio for success with clonidine versus placebo was 1.89 (95% confidence interval 1.30 to 2.74). There was a high incidence of dose-dependent side-effects, particularly dry mouth and sedation.

REVIEWERS' CONCLUSIONS

Based on a small number of trials, in which there are potential sources of bias, clonidine is effective in promoting smoking cessation. Prominent side-effects limit the usefulness of clonidine for smoking cessation.

Moxonidine versus placebo as an aid in smoking cessation

This study assessed the effects of moxonidine as an aid in smoking cessation in 166 heavily addicted smokers who were motivated to quit smoking completely. Recruitment was via advertisement. Patients were randomly allocated to receive double-blind placebo or moxonidine (0.1 mg once or twice daily) for 6 weeks. Brief counseling was provided. An encouragement letter was sent prior to the quit date. Success was defined as not smoking any cigarettes during weeks 3 - 6, an expired carbon monoxide level of < 10 ppm, and a plasma cotinine level of < 25 ng/ml. The study failed to demonstrate a statistically significant effect for moxonidine on either nicotine withdrawal symptoms or smoking cessation. Reported side effects were not different with moxonidine than with placebo, however. Copyright 2000 John Wiley & Sons, Ltd.

Clonidine for smoking cessation

BACKGROUND

Clonidine was originally used to lower blood pressure. It acts on the central nervous system and may reduce withdrawal symptoms in various addictive behaviours, including tobacco use.

OBJECTIVES

The aim of this review is to determine clonidine's effectiveness in helping smokers to quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group trials register. Date of the most recent search: October 1998.

SELECTION CRITERIA

We considered randomised trials of clonidine versus placebo with a smoking cessation endpoint assessed at least 12 weeks following the end of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of subjects, the dose and duration of clonidine therapy, the outcome measures, method of randomisation, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least twelve weeks follow-up in patients smoking at baseline. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effects model.

MAIN RESULTS

Six trials met the inclusion criteria. There were three trials of oral, and three of transdermal clonidine. Some form of behavioural counselling was offered to all participants in five of the six trials. There was a statistically significant effect of clonidine in one of these trials. The pooled odds ratio for success with clonidine vs placebo was 1.89 (95% confidence interval 1.30 to 2.74). There was a high incidence of dose-dependent side-effects, particularly dry mouth and sedation.

REVIEWER'S CONCLUSIONS

Based on a small number of trials, in which there are potential sources of bias, clonidine is effective in promoting smoking cessation. Prominent side-effects limit the usefulness of clonidine for smoking cessation.

Variants in the alpha2A AR adrenergic receptor gene in psychiatric patients

In various studies of psychiatric patients, alterations in adrenergic receptor (AR) expression or function have been suggested. Herein, the alpha2A AR gene was screened in 206 patients with schizophrenia, attention deficit hyperactivity disorder (ADHD), autism, alcohol dependence, or cocaine dependence. The entire coding region was examined for single base pair changes, using restriction endonuclease fingerprinting (REF), a screening method that can detect virtually 100% of mutations in 2-kb DNA segments. In the approximately 600 kb of screened sequence, six novel nucleotide changes were identified. The changes resulted in four missense changes (A25G, N251K, R368L, and K370N), and a sequence in the 3' untranslated region. In addition, a silent change (G363G) was found at high frequency in Asians and Native Americans. Of the four missense changes, two found in patients with alcohol/drug dependence occur in highly conserved amino acids, suggesting that these are of likely functional significance. As the alpha2A ARs are widely distributed both pre- and postsynaptically, and as many pharmacological agents with multiple effects target these receptors, the novel missense changes described herein may be candidates for involvement in alcohol/drug dependence, in other clinical disorders or traits, or in differential response to pharmacotherapy.

Dexmedetomidine alleviates ethanol withdrawal symptoms in the rat

The effect of dexmedetomidine, a selective alpha 2-adrenoceptor agonist, on ethanol withdrawal symptoms was studied in chronically ethanol-fed rats. After a 4-day ethanol intoxication period the rats were given s.c. injections of dexmedetomidine (3, 10, or 30 micrograms/kg) or saline (control group) at 10, 16, 22, and 39 h after the last dose of ethanol. The severity of ethanol withdrawal symptoms (rigidity, tremor, irritability, hypoactivity) was rated up to 58 h, blind to the treatments. The results showed that dexmedetomidine at doses 10 and 30 micrograms/kg significantly diminished the severity of the ethanol withdrawal reaction as measured by the sum score of the three most specific withdrawal signs (rigidity, tremor, and irritability). Dexmedetomidine at 10 micrograms/kg was the most effective dose, especially in the latter half of the withdrawal period (23-58 h after last dose of ethanol). The results suggest that dexmedetomidine in the treatment of ethanol withdrawal symptoms should be further studied.

[Clinical and laboratory changes before the development of delirium tremens]

Thirteen alcoholic male patients that developed delirium tremens (DT) after admission in a psychiatric hospital for treatment of alcoholism (group I) had their clinical and laboratorial records examined. The laboratory samples were taken during the phase previous at the DT. Data on this group were compared to those of two other groups of alcoholics--26 patients each--that did not develop DT in the present admission, with (group II) or without (group III) previous history of DT. The patients of group I had significantly lower average age and worse general conditions than the patients of group III. The frequency of elevated aminotransferases and hypomagnesemia was significantly higher in the group I and II than in the group III. The aminotransferases, especially the aspartate-aminotransferase, were significantly more elevated in the groups I and II.

Pain relief with low-dose intravenous clonidine in a child with severe burns

The case of an 11-year-old boy who suffered second and third degree burns to 78% of his body is reported. The large doses of morphine used as analgesia resulted in severe side effects: ventilatory dependence, impairment of gastrointestinal function and psychological disturbance. Intravenous lignocaine was added without benefit. The addition of low-dose intravenous clonidine, however, precipitated a dramatic reduction in morphine consumption with an attendant improvement in ventilatory, gastrointestinal and psychological functions.

Therapy of alcohol withdrawal syndrome in intensive care unit patients following trauma: results of a prospective, randomized trial

OBJECTIVES

To assess the effect of three different alcohol withdrawal therapy regimens in traumatized chronic alcoholic patients with respect to the duration of mechanical ventilation and the frequency of pneumonia and cardiac disorders during their intensive care unit (ICU) stay.

DESIGN

A prospective, randomized, blinded, controlled clinical trial.

SETTING

A university hospital ICU.

PATIENTS

Multiple-injured alcohol-dependent patients (n=180) transferred to the ICU after admission to the emergency room and operative management. A total of 180 patients were included in the study; however, 21 patients were excluded from the study after assignment.

INTERVENTIONS

Patients who developed actual alcohol withdrawal syndrome were randomized to one of the following treatment regimens: flunitrazepam/clonidine (n=54); chlormethiazole/haloperidol (n=50); or flunitrazepam/haloperidol (n=55). The need for administration of medication was determined, using a validated measure of the severity of alcohol withdrawal (Revised Clinical Institute Withdrawal Assessment for Alcohol Scale).

MEASUREMENTS AND MAIN RESULTS

The duration of mechanical ventilation and major intercurrent complications, such as pneumonia, sepsis, cardiac disorders, bleeding disorders, and death, were documented. Patients did not differ significantly between groups regarding age, Revised Trauma and Injury Severity Score and Acute Physiology and Chronic Health Evaluation II score on admission. In all except four patients in the flunitrazepam/clonidine group, who continued to hallucinate, the Revised Clinical Institute Withdrawal Assessment for Alcohol Scale decreased to <20 after initiation of therapy. ICU stay did not significantly differ between groups (p=.1669). However, mechanical ventilation was significantly prolonged in the chlormethiazole/haloperidol group (p=.0315) due to an increased frequency of pneumonia (p=.0414). Cardiac complications were significantly (p=.0047) increased in the flunitrazepam/clonidine group.

CONCLUSIONS

There was some advantage in the flunitrazepam/clonidine regimen with respect to pneumonia and the necessity for mechanical ventilation. However, four (7%) patients had to be excluded from the study due to ongoing hallucinations during therapy. Also, cardiac complications were increased in this group. Thus, flunitrazepam/haloperidol should be preferred in patients with cardiac or pulmonary risk. Further studies are required to determine which therapy should be considered.

Sedation for the critically ill neurologic patient

OBJECTIVE

To review the scientific basis for sedation of critically ill neurologic patients by summarizing the distinct neurophysiologic disturbances present in this population and presenting the central nervous system effects of sedative agents to permit optimal drug therapy.

DATA SOURCES

Review of the English language clinical and scientific literature using MEDline data search.

STUDY SELECTION

Literature references were selected through a key word search of sedative therapy, drugs used for sedation, and specific neurologic disorders and processes to provide an in-depth overview of sedative drug mechanisms of action, effects on neurophysiology and intracranial dynamics, pharmacokinetics, and toxicity profile. Special emphasis was placed on neurologic side effects.

DATA EXTRACTION

Clinical and scientific literature was reviewed and data relevant to neurophysiologic effects of sedative drug therapy were summarized. Recommendations for institution of sedative therapy and of particular agents were made as a result of analysis of all pooled data.

DATA SYNTHESIS

Critically ill patients with neurologic pathology present as a unique subset of individuals cared for in an acute care setting. Because monitoring of neurologic patients requires frequent assessment of the neurologic examination, the goal of sedative therapy should be to enhance, or to minimally perturb elicitation of the examination. Neurophysiologic disturbances introduce distinct risks for sedation and require their identification and understanding before the initiation of any sedative therapy. Sedative drugs, in particular, act to disturb central nervous system function and their effects may result in diagnostic confusion and further neurologic deterioration. The pharmacokinetic and neurophysiologic actions of the common classes of sedative agents, such as benzodiazepines, opioids, barbiturates, and neuroleptics, as well as ketamine, propofol, and clonidine are discussed. Recommendations are presented based on the specific type of sedation required and the underlying neurologic disturbance. Several specific examples, including head trauma, neuromuscular disease, and alcohol withdrawal, are provided.

CONCLUSIONS

Preservation of the neurologic examination is paramount in documenting clinical improvement or deterioration in the critically ill neurologic patient. Pharmacologic sedation in this unique population of acute care patients requires careful consideration of the underlying neurophysiologic disturbances and potential adverse effects introduced by sedative drugs.

Effect of clonidine on liver oxygen extraction during alcohol withdrawal in man

Since catecholamines can alter splanchnic oxygen transport and extraction, the suppression of sympathetic overactivity during alcohol withdrawal might improve hepatic oxygen extraction. Therefore, this study investigated the effects of clonidine, a centrally-acting alpha 2-agonist which reduces sympathetic nervous outflow, on splanchnic oxygen transport and extraction in 13 patients with chronic alcoholism during alcohol withdrawal. All patients had elevated transaminases and steatosis at liver biopsy and were withdrawn from alcohol 51 +/- 15 h (mean +/- SD) before the study. Hepatic blood flow, cardiac output and the oxygen contents were measured in the radial and pulmonary arteries and in the hepatic veins before and 45 min after intravenous administration of clonidine, 150 micrograms. Basal hepatic blood flow was inversely correlated with norepinephrine plasma concentrations (r = -0.63, p < 0.025). After clonidine administration, the decrease in plasma norepinephrine correlated with the norepinephrine basal value (r = 0.889, p < 0.001), and splanchnic oxygen extraction increased (from 40 +/- 15 to 49 +/- 17%, p < 0.025). After clonidine administration, splanchnic oxygen extraction was correlated with the decrease in plasma norepinephrine (r = 0.72, p < 0.01). Arterial lactate concentration decreased (from 0.74 +/- 0.20 to 0.64 +/- 0.23 mmol/l, p < 0.01). These results suggest that defective liver oxygen extraction might occur during alcohol withdrawal as a result of sympathetic nervous hyperactivity. Alterations in the hepatic microcirculation during withdrawal might be related to catecholamine secretion and be controlled by pharmacological manipulation.

Propranolol versus diazepam in the management of the alcohol withdrawal syndrome: double-blind controlled trial

Thirty-seven male alcoholics admitted electively for detoxification were randomized to treatment with either diazepam or propranolol. Subjects were comparable both in age and in duration and quantity of alcohol consumed. Admission laboratory parameters did not distinguish between the groups. Eleven subjects required no medication to control withdrawal signs/symptoms. Both groups showed improvement in blood pressure, pulse, and withdrawal tremor. None of the subjects randomized to diazepam manifested withdrawal seizures or hallucinations. By contrast, one subject in the propranolol group had a single withdrawal seizure. Another subject manifested increasing withdrawal that required parenteral paraldehyde treatment. Thus, this study confirms that a significant number of subjects admitted electively for alcohol withdrawal can be managed without medication. Minor tranquilizers still remain the "gold standard" for management of the withdrawal syndrome.

Alpha-2-adrenoceptor sensitivity in early alcohol withdrawal

Growth hormone (GH), blood pressure, and pulse rate responses to clonidine (100 micrograms IV) were studied three times during the first week of alcohol withdrawal in 19 alcohol-dependent patients. Fifteen healthy men were used as controls. The results suggest reduced sensitivity of the alpha-2-adrenoceptors involved in GH secretion for at least 1 week after the end of alcohol intake. In contrast, very short-lasting subsensitivity was found in the alpha-2-adrenoceptors regulating blood pressure.

Pharmacological adjuncts for the treatment of withdrawal syndromes

Alternative explanations for symptoms that occur during the period of drug (medical or nonmedical) withdrawal are examined. These symptoms are not necessarily due to the discontinuation of the drug and should be considered when treating a patient for a withdrawal syndrome. The rationale behind treating withdrawal syndromes and criteria to consider for hospitalizing a patient during the withdrawal period are discussed. The main focus of this article is the appropriate use of prescription drugs for treating withdrawal syndromes. In addition, protocols of the Drug Detoxification, Rehabilitation, and Aftercare Project of the Haight Ashbury Free Clinics are reviewed in detail. Finally, information is provided on some potentially promising medications that are currently being investigated for the treatment of withdrawal.

The effect of medetomidine on GABA and benzodiazepine receptors in vivo: lack of anxiolytic but some evidence of possible stress-protective activity

Medetomidine, a new selective alpha 2-adrenoceptor agonist, potentiated bicuculline seizures in mice. In vivo pretreatment with medetomidine in mouse cerebral cortex reduced dose-dependently (2.5-100 micrograms/kg) GABA-potentiated 3H-flunitrazepam binding. The affinity of 3H-muscimol was also reduced by medetomidine. This effect of medetomidine on GABA-potentiated benzodiazepine binding was reversed by pretreatment with atipamezole (1 mg/kg), a specific alpha 2-antagonist. In an elevated plus-maze model of anxiety medetomidine (0.5-10 micrograms/kg) was inactive both in rats and mice and did not antagonize the behavioural effects of an anxiogenic beta-carboline, DMCM. However, at lower doses medetomidine (10 but not 50 micrograms/kg) antagonized the swimming stress caused increase of central benzodiazepine binding sites (labeled with 3H-Ro 15-1788) in mouse cerebral cortex. The increase of peripheral benzodiazepine binding sites on brain and heart cryostat cut slices caused by stress was also antagonized by pretreatment with medetomidine. The behavioural and biochemical data obtained in this study are evidence that medetomidine does not have anxiolytic effect but may have, in lower doses, stress-protective activity.

Pharmacotherapies for alcoholism: promising agents and clinical issues

The past 10 years have witnessed important advances in research on pharmacotherapy for alcoholism. Promising drugs are discussed under six headings: agents to treat alcohol withdrawal; anticraving agents; agents that make drinking an aversive experience; agents to alleviate concomitant psychiatric problems; agents to treat concurrent drug abuse; and amethystic ("sobering-up") agents. Research on the drug classes is summarized and clinical issues surrounding specific agents and alcoholism pharmacotherapy in general are discussed. Finally, long-range therapeutic implications of recent findings on the actions of alcohol on basic mechanisms of the brain are offered.

Antismoking products

Nicotine is the addictive substance in tobacco and its withdrawal is responsible for a range of unpleasant symptoms after smoking cessation. Although it produces acute physiological effects, nicotine alone is not carcinogenic and does not appear to cause the vascular disease associated with smoking. Nicotine replacement has been shown to be a safe and effective pharmacological treatment for tobacco dependence in certain smokers. Its efficacy is greatest when prescribed for those who are motivated and highly nicotine-dependent. It is probably not indicated for smokers with a low degree of nicotine dependence. Studies of nicotine chewing gum conducted in special referral clinics have generally produced positive results, whereas those conducted in community practice settings have shown a smaller benefit when compared with placebo. When the results of all published placebo-controlled trials are pooled the typical improvement in smoking cessation rate is 40% (odds ratio continued smoking 0.6; 95% confidence interval 0.5-0.71; P less than 0.00001). The best results with nicotine chewing gum have been obtained with multicomponent programmes which have included some counselling and ongoing follow up and support. Early reports of success with a transdermal nicotine preparation suggest that it may have similar efficacy to nicotine gum. Clonidine administered orally or transdermally has also been shown to reduce tobacco withdrawal symptoms but requires more convincing evidence of long-term efficacy before it can be recommended for routine use. Currently available over-the-counter products, apart from nicotine chewing gum, have not been shown to be effective.

Alcoholism and panic disorder: is the comorbidity more than coincidence?

Studies on alcoholic patients have found a higher than expected prevalence of panic disorder, and suggest a positive correlation between the level of alcohol consumption and severity of anxiety. Conversely, there is an increased prevalence of alcoholism among patients with panic disorder and their blood relatives. A comparison of symptoms, physiological and neurochemical changes known to occur in both alcohol withdrawal and panic disorder reveals a degree of similarity between the 2 conditions. Based on the data, we propose that the chemical and cognitive changes occurring as the result of repeated alcohol withdrawals may kindle and condition coincidence of panic attacks in susceptible individuals. Implications of our postulates for treatment of alcohol withdrawal and panic disorder in alcoholics and for future studies are discussed.

The role of buspirone in the management of alcohol withdrawal: a preliminary investigation

One hundred eighteen patients, 77 men and 23 women ranging in age from 18 to 70 years of age, admitted to an inpatient facility in Central New York were administered buspirone HCl for treatment of the alcohol withdrawal syndrome. Although one patient had an unwitnessed seizure, none of the subjects required discontinuance of buspirone HCl because of symptoms of dizziness, nausea, headache, nervousness, or lightheadedness, typical side effects described by the manufacturer. All but one of the individuals given buspirone HCl for alcohol detoxification completed that phase of treatment within six days in a manner which effectively controlled their withdrawal symptoms. The findings were suggestive of an important role for buspirone HCl in the detoxification of the alcohol-dependent patient using a pharmacologic agent other than traditional medications such as benzodiazepines, phenobarbital, beta blockers, magnesium sulphate, or clonidine.

Combining clonidine and nicotine replacement for treatment of nicotine withdrawal

The U.S. Surgeon General's 1988 report on nicotine addiction has increased the need for the substance abuse treatment community to become more involved in smoking cessation programs. A unique approach to nicotine detoxification has been developed at the Haight Ashbury Free Clinics' Drug Detoxification, Rehabilitation and Aftercare Project. After an evaluation by a physician, a thorough explanation of the treatment plan, and if the patient is interested, a combination of clonidine via the transdermal patch (Catapres-TTS) and of nicotine replacement via nicotine polacrilex (Nicorette) is used. By combining a Nicorette taper with clonidine, the physician can control the rate of nicotine withdrawal (Nicorette) and the extent to which withdrawal symptoms are treated (clonidine). This appears to be an effective, comfortable method for detoxification from cigarettes and nicotine. Its use should prove helpful as an adjunct to a comprehensive smoking cessation program.

Alcohol withdrawal syndrome: clinical and hormonal responses to alpha 2-adrenergic agonist treatment

Lofexidine (L) was compared to placebo (P) in a random double blind placebo controlled study of 23 healthy alcoholics in withdrawal. In serial alcohol withdrawal syndrome (AWS) scales, P greater than L for first 18 hr. The major changes in AWS were in blood pressure and pulse, while restlessness or diaphoresis did not show faster normalization with L vs. P. Other ratings of withdrawal intensities and craving by patients were similar in both P and L. There were no differences in the rate of patient completion, or appearance of hallucinations by group. Plasma catecholamines were in the high ranges, similar in both groups at 0 and 3 hr, but after 5 hr P greater than L for norepinephrine (but not epinephrine or dopamine). The data suggest L has pharmacological effects on some objective, catecholamine related, components of alcohol withdrawal, with little effect on others. L type treatment of alcoholics in withdrawal is promising, modestly effective and warrants further study.

The treatment of alcohol withdrawal

Abrupt cessation of regular use of alcohol in a dependent person causes a withdrawal syndrome that may range from mild to extremely severe. Most patients require pharmacologic intervention, especially those with severe symptoms. Historically, the pharmacotherapy of alcohol withdrawal has involved a wide variety of agents. Benzodiazepines are currently preferred due to their consistently high degree of efficacy and laudable record of safety. In addition, beta blockers and clonidine are useful, as both effectively combat the hypertension and tachycardia commonly associated with withdrawal. They are ineffective as anticonvulsants; however. Opinions differ concerning the best treatment for withdrawal seizures. Prophylaxis with benzodiazepines may be all that is required, although some authors advocate the use of phenytoin for 5 days, especially in persons with a history of prior seizures during alcohol withdrawal. Once established, delirium tremens are difficult to treat. Benzodiazepines are most commonly used to provide sedation, and extremely large doses may be required. Careful clinical assessment is essential to the proper treatment of patients undergoing alcohol withdrawal since the coexistence of medical problems may complicate the condition.

Is clonidine useful in the treatment of alcohol withdrawal?

The comparative efficacy of clonidine and chlormethiazole has been examined in the management of acute alcohol withdrawal. A double blind randomized study was conducted in consecutive patients admitted to a hospital detoxification unit. Patients were assessed regularly by a standard alcohol withdrawal rating-scale. Thirty-two patients received either clonidine or chlormethiazole in reducing dosages over 96 hr. All the patients receiving chlormethiazole had uneventful withdrawals. However, eight patients treated with clonidine were withdrawn from the trial due to hallucinations (two), seizures (two), symptomatic orthostatic hypotension (three) or drowsiness (one), indicating that clonidine is less effective than chlormethiazole in the prevention of the major manifestations of alcohol withdrawal.

Use of an objective clinical scale in the assessment and management of alcohol withdrawal in a large general hospital

A modified version of the Clinical Institute Withdrawal Assessment Scale (CIWA) was used in the management of alcohol withdrawal in a general hospital. Patients who developed seizures or confusion were noted to score higher on the scale, even before these complications, than patients who remained uncomplicated (21.7 +/- 1.2 compared to 15.6 +/- 0.55). When the score was used as a guide for treatment, it was found that patients scoring greater than 15 were at significantly increased risk of severe alcohol withdrawal if they remained untreated (RR, 3.72; 95% confidence interval, 2.85-4.85). The higher the score the greater this relative risk. Some patients however, still suffered complicated withdrawals although their scores were low or they were apparently adequately treated. It is concluded that the use of an objective clinical scale of alcohol withdrawal is valuable in a general hospital to identify those patients in early withdrawal who need sedation to avoid complication. There will however, be a small group of patients whose clinical course will be difficult to predict and further work is needed to determine the reasons for this.

Acute ethanol poisoning and the ethanol withdrawal syndrome

Ethanol, a highly lipid-soluble compound, appears to exert its effects through interactions with the cell membrane. Cell membrane alterations indirectly affect the functioning of membrane-associated proteins, which function as channels, carriers, enzymes and receptors. For example, studies suggest that ethanol exerts an effect upon the gamma-aminobutyric acid (GABA)-benzodiazepine-chloride ionophore receptor complex, thereby accounting for the biochemical and clinical similarities between ethanol, benzodiazepines and barbiturates. The patient with acute ethanol poisoning may present with symptoms ranging from slurred speech, ataxia and incoordination to coma, potentially resulting in respiratory depression and death. At blood alcohol concentrations of greater than 250 mg% (250 mg% = 250 mg/dl = 2.5 g/L = 0.250%), the patient is usually at risk of coma. Children and alcohol-naive adults may experience severe toxicity at blood alcohol concentrations less than 100 mg%, whereas alcoholics may demonstrate significant impairment only at concentrations greater than 300 mg%. Upon presentation of a patient suspected of acute ethanol poisoning, cardiovascular and respiratory stabilisation should be assured. Thiamine (vitamin B1) and then dextrose should be administered, and the blood alcohol concentration measured. Subsequent to stabilisation, alternative aetiologies for the signs and symptoms observed should be considered. There are presently no agents available for clinical use that will reverse the acute effects of ethanol. Treatment consists of supportive care and close observation until the blood alcohol concentration decreases to a non-toxic level. In the non-dependent adult, ethanol is metabolised at the rate of approximately 15 mg%/hour. Haemodialysis may be considered in cases of a severely ill child or comatose adult. Follow-up may include referral for counselling for alcohol abuse, suicide attempts, or parental neglect (in children). The ethanol withdrawal syndrome may be observed in the ethanol-dependent patient within 8 hours of the last drink, with blood alcohol concentrations in excess of 200 mg%. Symptoms consist of tremor, nausea and vomiting, increased blood pressure and heart rate, paroxysmal sweats, depression, and anxiety. Alterations in the GABA-benzodiazepine-chloride receptor complex, noradrenergic overactivity, and hypothalamic-pituitary-adrenal axis stimulation are suggested explanations for withdrawal symptomatology.(ABSTRACT TRUNCATED AT 400 WORDS)